1. Technical Field
The disclosed embodiments generally relate to the field of documents and files containing embedded information.
2. Description of the Related Art
In environments in which multiple users share or exchange data in the form of documents or document files, there is a need to permit the multiple users to access a particular document in a “public space” available to all, or to retrieve or copy a portion of a document on a personal computer or printing device. Similarly, there is a need for a mechanism by which a user who has created a document or file can place the work in a public space to be viewed by others, and if desirable edited by others. At the same time, it is desirable, in a shared-files system, to have some mechanism for security with respect to publicly available documents, so that there can be some order and control over the contents of documents.
One method of providing security in a document access system is to associate an object with each individual file that is contained in a file system. An “object” is a set of computer-readable code that describes access properties (e.g., read and/or write permissions), hierarchical relations, and/or other properties of the file. The object may be permanently associated with the file. Whenever a user desires to access a file, the document access system first locates the object for that file and performs one or more tasks based on the content of the object. For example, the tasks may include retrieving the requested file, identifying or retrieving related file, or determining what rights the user has to access and/or modify the file. An example of such a system is disclosed in U.S. Pat. No. 5,930,801, the disclosure of which is incorporated herein by reference in its entirety.
In a physical document, the object data may be contained in, or the object may be located based on information contained in, an embedded data block (EDB) that is printed on the document. An EDB is a two-dimensional image symbology for the storage and retrieval of data. EDBs are composed of embedded data characters, some of which are encoded to define a synchronization frame and others of which are encoded to carry user/application-specific information. Patents relating to the encoding of EDBs include U.S. Pat. Nos. 5,453,605, 5,449,896, 5,572,010, 5,862,271, and 5,939,703, the disclosures of each of which are incorporated herein by reference.
One example of an EDB is a glyph block. Glyph blocks encode information, for example, text, data and graphics, in thousands of tiny glyphs. Other types of EDBs include, and are not limited to, bar codes, watermarks, and other embedded computer-readable images or text.
Prior art object-based and EDB-based management systems only permit the relation of one document to an object. In the prior art, there has been no mechanism to allow for the inclusion of a structured collection of documents, or individual portions of documents, each potentially with its own state, access rights, operations and/or workflow information, within a single object.
The disclosure contained herein describes attempts to address one or more of the problems described above.